Osman Alialso called Us̄mān ʿalī KhānʿAlī Khan, Mīr ( born April 6, 1886 , Hyderābād Hyderabad, India—died Feb. 24, 1967 , Hyderābād Hyderabad ) nizam (ruler) of Hyderābād Hyderabad princely state in India in the period 1911–48 and its constitutional president until 1956. Once one of the richest men in the world, he ruled over a state the size of Italy.

After a private education, Osman Ali succeeded his father, Maḥbūb ʿAlī KhānKhan, the sixth nizam, on Aug. 29, 1911. Encouraging financial reform, he led the state of Hyderābād Hyderabad to an enviable credit position; it issued its own currency notes and coins and acquired ownership of a major railway network. In 1918 he patronized the founding of Osmania University, HyderābādHyderabad. Unlike some neighbouring princes, he maintained the feudal character of his state and showed little interest in the increasing voice of the Hindu majority among his people, although he spent considerable sums to improve their living conditions. In World War II his state provided naval vessels and two Royal Air Force squadrons; in 1946 he was awarded the Royal Victorian Chain.

Supported by the Majlis Ittehad al-Muslimin (movement for Muslim unity) with its private army, the RazākārsRaẕākārs, Osman Ali refused to submit to Indian sovereignty in 1947 when Britain withdrew. Appealing to the special alliance he claimed with the British, he placed his case for the full independence of his state before the United Nations. He rejected an Indian ultimatum that he surrender his authority but, in September 1948, was obliged to yield to Indian troops. He was made president (rajpramukh) of the state but had to accept the advice of Cabinet ministers responsible to an elected legislature until his state was absorbed by neighbouring states in the 1956 general reorganization of boundaries. He then lived in splendid retirement with 3 wives, 42 concubines, 200 children, 300 servants, and aging retainers, including a private army. He provided pensions for some 10,000 princelings and serfs of his former empire and aided Muslim refugees from Palestine. He was created Knight Grand Commander of the Star of India in 1911 and Knight Grand Cross of the British Empire in 1917.